Wang Xun, Zhu Shanhui, Wang Sen, He Yue, Liu Yang, Wang Jianguo, Fan Weibin, Lv Yongkang
Key Laboratory of Coal Science and Technology, Ministry of Education and Shanxi Province, Taiyuan University of Technology Taiyuan 030024 Shanxi China
State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences Taiyuan 030001 PR China
RSC Adv. 2019 Jan 29;9(7):3868-3876. doi: 10.1039/c8ra09972c. eCollection 2019 Jan 25.
Hydrodeoxygenation (HDO) of guaiacol to cyclohexane, important for bio-oil upgrading, is usually performed at high reaction temperature (≥200 °C). In this work, low temperature transformation of guaiacol to cyclohexane was achieved at 140 °C over non-noble metal Ni/SiO and various zeolites. Among zeolites tested (HUSY, HMOR, Hβ, HZSM-5, SAPO-34), Hβ zeolite exhibited superior catalytic activity due to its appropriate pore structure and acid strength. The open pore with three-dimensional structure of Hβ facilitates the diffusion of guaiacol and intermediates. Meanwhile, weak acid strength of Hβ efficiently reduces the competitive adsorption of guaiacol, and then promotes the dehydration of intermediate 2-methoxycyclohexanol. Moreover, the catalytic performance in guaiacol HDO to cyclohexane is also closely related to Si/Al ratio of Hβ. Owing to its moderate acid density, the maximum yield of cyclohexane reaches 91.7% on Hβ(Si/Al = 50) combined with Ni/SiO at 140 °C, which is the lowest temperature ever reported over non-noble metal catalysts.
愈创木酚加氢脱氧生成环己烷对生物油提质很重要，通常在较高反应温度（≥200℃）下进行。在本工作中，在140℃下，非贵金属Ni/SiO和各种沸石可实现愈创木酚向环己烷的低温转化。在所测试的沸石（HUSY、HMOR、Hβ、HZSM - 5、SAPO - 34）中，Hβ沸石因其合适的孔结构和酸强度而表现出优异的催化活性。Hβ的三维结构开放孔有利于愈创木酚和中间体的扩散。同时，Hβ的弱酸强度有效降低了愈创木酚的竞争吸附，进而促进了中间体2 - 甲氧基环己醇的脱水。此外，愈创木酚加氢脱氧生成环己烷的催化性能也与Hβ的硅铝比密切相关。由于其适度的酸密度，在140℃下，Hβ（硅铝比 = 50）与Ni/SiO组合时，环己烷的最大产率达到91.7%，这是在非贵金属催化剂上报道过的最低温度。
